I agree with the "playing host" point of view. I enjoy having friends over and sharing my passion with them. Most are delighted my passion comes in liquid form
As a guest, I would never want them to shell out for anything I might choose to share with them.
OTOH, I have thought that some time during the Octoberfest season, when I had more beer on tap than I could possibly think about drinking myself, I would pull the kegerator outdoors one weekend, invite a bunch of people over and put a donation jar there to be donated to a good cause.
Sounds like a great idea, right? Also illegal. At least in the State of CT, even a charity can not "sell" homebrew for fundraising purposes.